Cannot publish table without primary keys

Cannot publish table without primary keys

I've used the following link Sqltraining to create a job that will keep
historical data of my database growth. However, since I have several
different instances of servers across locations, I will be using a
previously replicated database and add the table as per step #2 in the
link. However, I cannot publish the new article/ table because it does not
have primary key. I am confused as to which one should be the primary key.
Can anyone please help. Thanks.